Motorized disconnect system and operation methods

ABSTRACT

Methods and systems are provided for a motorized disconnect operable to selectively engage and disengage two rotating components of a vehicle drivetrain. As one example, a motorized disconnect system is provided that operates via an electric motor and includes a shifter assembly with an oscillating gear track and cam profile for rotating the shifter assembly while moving it in an axial direction to selectively couple two rotating components.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. Non-Provisional patentapplication Ser. No. 15/488,255 entitled “MOTORIZED DISCONNECT SYSTEMAND OPERATION METHODS” filed on Apr. 14, 2017. U.S. Non-Provisionalpatent application Ser. No. 15/488,255 is a continuation of U.S.Non-Provisional patent application Ser. No. 14/678,245 entitled entitled“MOTORIZED DISCONNECT SYSTEM AND OPERATION METHODS” filed on Apr. 3,2015, now U.S. Pat. No. 9,656,548. U.S. Non-Provisional patentapplication Ser. No. 14/678,245 claims priority to U.S. ProvisionalPatent Application No. 61/980,425, entitled “MOTORIZED DISCONNECT SYSTEMAND OPERATION METHODS,” filed on Apr. 16, 2014. U.S. Non-Provisionalpatent application Ser. No. 14/678,245 claims further priority to U.S.Provisional Patent Application No. 62/051,864, entitled “MOTORIZEDDISCONNECT SYSTEM AND OPERATION METHODS,” filed on Sep. 17, 2014. Theentire contents of each of the above-identified applications are herebyincorporated by reference for all purposes.

FIELD

The present application relates generally to a motorized disconnectsystem for engaging and disengaging two rotating components of avehicle.

SUMMARY/BACKGROUND

Modern vehicles often incorporate one or more drivetrain modes forproviding power from an engine to the driven wheels. For example, avehicle with only a two-wheel drive system, or 4×2 mode, may providepower via one or a series of rotating shafts to two wheels of thevehicle. Vehicles such as compact cars may use a front wheel drivesystem with power provided to the two front wheels. In other, oftenlarger vehicles, it is often desirable to incorporate both two-wheeldrive and four-wheel drive driving modes, wherein power may beselectively distributed to two wheels in one mode and four wheels inanother mode. Vehicles of different sizes often incorporate two-wheeldrive of the rear wheels and four-wheel drive for the purpose ofenabling better handling during varying traction conditions while stillbeing able to switch to two-wheel drive to reduce fuel consumption andreduce wasted power.

For vehicles with switchable drive modes, devices and systems are neededfor engaging and disengaging drivetrain components such as axles andshafts. As such, disconnect assemblies are used that often involve aform of clutch that can move to connect or disconnect two rotatablecomponents such as two shafts. The disconnect assemblies can be placedin a variety of areas in the drivetrain of a vehicle, including at thewheel ends, at one or more axles, or along one of the drive shafts.Through the use of disconnect systems, vehicles can be made moreversatile by having the ability to switch between different drive modesdepending on the driving conditions and operator desire.

In some powertrain disconnecting systems, vacuum directed from thevehicle engine is used as the motive or actuating force that powers thedisconnecting systems. In particular, the disconnecting system actuatorsmay be powered by the vacuum. In many systems, the vacuum is directedvia a passage from the intake manifold of the gasoline-fueled engine.Due to this, the vacuum level, or amount of force or pressure availablefrom the vacuum, may vary as engine throttle settings change along withengine load. For turbocharged diesel-fueled engine systems, vacuum maybe generated by an auxiliary pump. For both gasoline and turbochargeddiesel engine systems, the vacuum level (amount of pressure available)may be limited or vary due to the effects of altitude. Furthermore,temperature changes can also cause pressure fluctuations in the vacuumlevel, thereby causing fluctuations in movement of the disconnectactuator which may result in undesirable movement of disconnectcomponents such as the diaphragm and clutch components. Additionally, insome vehicles vacuum may not be readily available since various vehicleaccessory systems may not be powered by vacuum, or the vehicle may bedesigned to remove engine intake connections such as vacuum lines inorder to enhance engine control and performance. Finally, vacuum-poweredpowertrain disconnect systems are becoming less desirable with moreadvanced vehicle design. As such, powertrain disconnect systems areneeded that are powered by sources other than vacuum and feature designsconducive to modern vehicle systems. The inventors herein haverecognized the above issues and developed various approaches to addressthem.

Thus in one example, the above issues associated with vacuum powereddisconnects may be at least partially addressed by a motorizeddisconnect assembly, comprising: a shifter assembly including anundulating gear track undulating between two ends of the shifterassembly in a direction of a rotation axis of an interfacing, firstshaft, the gear track trapped between fixed cam guides. In this way, acompact disconnect assembly is provided that is powered by an electricmotor located on-board the disconnect assembly and does not rely onvacuum power. Also, the undulating gear track may allow the electricmotor to be driven in only a single direction during one or moreparticular shift commands or modes, allowing the shifter assembly tomove back and forth along an axial direction.

In another example, the motorized disconnect assembly may be placed in aself-contained housing and disposed between two rotating components.This may allow for a more compact design compared to other disconnectassemblies. Also, as described in further detail later, the placement ofthe disconnect housing may protect and substantially isolate internalcomponents from external contamination such as dust and unwanted greaseand/or oil. The isolation of inner components may aid in increasing thedurability and longevity of the disconnect assembly, thereby reducingrepair and replacement costs for its continued operation.

The proposed powertrain disconnect system may include an electricmotorized disconnect that may alleviate the aforementioned issuesassociated with vacuum-powered disconnects. An electric motor-powereddisconnect may not fluctuate as vacuum-powered disconnects do.Furthermore, the disconnect assembly also features a shifter assemblythat rotates and moves axially via a worm drive. The axial movement maybe caused by a worm gear engaging an oscillating (non-planar or curved)gear track that in turn moves the shifter assembly along the axialdirection as the shifter assembly rotates. This movement may be used tocause engagement and disengagement between two rotating components, sucha drive shafts and/or axles.

It should be understood that the summary above is provided to introducein simplified form a selection of concepts that are further described inthe detailed description. It is not meant to identify key or essentialfeatures of the claimed subject matter, the scope of which is defineduniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a simplified powertrain of a vehicle in accordance with thepresent disclosure.

FIG. 2 shows a motorized disconnect for selectively engaging tworotating components of a vehicle drivetrain.

FIG. 3 shows a shifter assembly of the motorized disconnect of FIG. 2 inan exploded view.

FIG. 4 shows a cross-sectional view of the motorized disconnect of FIG.2

FIG. 5 shows additional views of the motorized disconnect of FIG. 2.

FIG. 6 shows a diagram of a magnetic bi-polar sensor and polarizedmagnets for detecting the position of the motorized disconnect.

FIG. 7 shows a flow chart depicting general operation of shiftingbetween 4×4 and 4×2 positions of the motorized disconnect.

FIG. 8 shows a diagram of a controller for commanding shiftingoperations of the motorized disconnect of FIG. 2.

FIG. 9 shows another example of a motorized disconnect assembly attachedto a wheel end.

FIG. 10 shows 4×2, 4×4, and blocked shift positions of the motorizeddisconnect assembly of FIG. 9.

FIG. 11 shows a cross-section and detail view of the motorizeddisconnect of FIG. 9.

FIG. 12 shows the control assembly of the motorized disconnect of FIG.9.

FIG. 13 shows a series of magnets positioned around a shifter assemblyof the motorized disconnect of FIG. 9.

FIG. 14 shows deflected positions of springs of the motorized disconnectof FIG. 9.

FIGS. 15 and 16 show a flow charts depicting general operation ofshifting between 4×4 and 4×2 positions of the motorized disconnectlocated on the left or right side of the vehicle.

FIG. 17 shows a diagram of a controller for commanding shiftingoperations of the motorized disconnect of FIG. 9.

FIGS. 18-22 show schematics of a position of a center motorizeddisconnect for a vehicle.

FIGS. 23-27 show schematics of the center motorized disconnect for anaxle of a vehicle.

FIGS. 2-5, 9-14, and 23-27 are drawn approximately to scale.

DETAILED DESCRIPTION

The following detailed description provides information regarding amotorized disconnect assembly and the methods of operation thereof forselectively connecting rotating components of a vehicle. An exampleembodiment of a vehicle powertrain is shown in FIG. 1, including anengine, a transmission, various axles and shafts, and wheels forproviding motive power to the vehicle. One embodiment of a motorizeddisconnect operated by an electric motor is shown in FIG. 2 which may beused with the powertrain of FIG. 1. A component of the motorizeddisconnect of FIG. 2, a shifter assembly, is shown in FIG. 3. Additionalviews of the motorized disconnect are shown in FIGS. 4 and 5. A diagramshowing a magnetic bi-polar sensor and associated system is displayed inFIG. 6 for detecting position of the shifter assembly. A method foroperating the motorized disconnect is depicted in FIG. 7 while a simpleschematic diagram of a controller located on the disconnect assembly isshown in FIG. 8. In one example, the motorized disconnect assembly maybe a wheel end disconnect positioned at a wheel end of a vehicle. Anembodiment of a motorized disconnect assembly utilized as a wheel enddisconnect is shown in FIGS. 9-14 while a general operation scheme ofthe disconnect is shown in FIGS. 15 and 16. A simple schematic diagramfor the controller of the disconnect of FIG. 9 is shown in FIG. 17. Inanother example, the motorized disconnect assembly may be a centermotorized disconnect positioned on a front or rear wheel axle, as shownin FIGS. 18-22. An embodiment of a center motorized disconnect assemblyis shown in FIGS. 23-27.

Regarding terminology used throughout this detailed description, vehicleoperation where only two wheels receive power from the engine may bereferred to as two-wheel drive, or 2WD, or 4×2. The correspondingposition of the motorized disconnect may be referred to as a 4×2position. Alternatively, vehicle operation where all four wheels receivepower from the engine may be referred to as four-wheel drive, or 4WD, or4×4. The corresponding position of the motorized disconnect may bereferred to as a 4×4 position. Also, the motorized disconnect mayselectively engage two rotating components. The system may also beapplied in so-called all-wheel drive (AWD) applications. In someembodiments, these components may be axles, shafts, or other devicesused in the drivetrain of the vehicle for transmitting rotational power.

Modern vehicles may be operated by a large variety of drivetrain systemsthat involve selectively powering different wheels according todifferent operating conditions and/or operator (i.e. driver) commands.For example, all-wheel drive vehicles may provide power to two collinearwheels during a first operating mode, and upon detection of slippage mayalso provide power to one or more of the remaining wheels. In otherexamples, a smaller vehicle, such as a passenger car, may permanentlyprovide power to only the front two wheels of the vehicle in order toincrease fuel economy (front two-wheel drive). Yet in other examples, avehicle may be configured to selectively switch between a two-wheeldrive and a four-wheel drive mode, wherein during the four-wheel drivemode all four wheels receive power. There are advantages anddisadvantages to each vehicle drivetrain, and the particular utility andanticipated function of each vehicle may aid in determining whichdrivetrain to incorporate.

FIG. 1 shows a simple diagram of a powertrain 100 of a vehicle. In thisdiagram, the body of the vehicle along with many other components areremoved for better viewing of powertrain 100. It is noted that thepowertrain includes the components seen in FIG. 1 while a drivetrain mayrefer to the components of FIG. 1 excluding the engine and transmission,described further below. According to the powertrain configuration, thevehicle of FIG. 1 may be have a selective 4WD drivetrain, wherein therear wheels are powered in a rear-wheel drive mode (or 2WD mode) and allfour wheels are powered in a 4WD mode, the 4WD drive mode different thanthe 2WD mode. Many utility vehicles such as larger trucks, all-terrainvehicles, and sports utility vehicles may incorporate rear-wheel driverather than front-wheel drive for various reasons. One reason may bethat rear-wheel drive is more conducive to load hauling or pulling, suchas towing via a trailer connected to the rear of the vehicle.

In FIG. 1, a right rear wheel 101 and left rear wheel 102 are positionedat the rear of the vehicle, that is, the end located behind an operatorof the vehicle. In this example, left, right, front, and rearorientations are given according to the perspective of the operator ofthe vehicle. Directional arrows for the front, rear, left, and rightorientations are shown in FIG. 1. Accordingly, a right front wheel 103and a left front wheel 104 are positioned at the front of the vehicle.

Power from the vehicle of FIG. 1 is generated by an internal combustionengine 110 having multiple cylinders. Engine 110 can be a fueled bygasoline or diesel according to the specific vehicle, and in the presentexample engine 110 contains six cylinders configured in a V orientation,forming a V6 engine. It is understood that engine 110 may be configuredin different orientations and contain a different number of cylinderswhile providing power in a similar fashion as seen in FIG. 1. A shaftpowered by engine 110 may be directly coupled to a transmission 115providing the necessary gearing for driving the vehicle. Transmission115 may be a manual or automatic transmission according to therequirements of the vehicle system. A rear drive shaft 131 may beconnected to transmission 115 as an output of the transmission,providing power to the rear end of the vehicle.

During the aforementioned 2WD mode of powertrain 100, wheels 101 and 102are powered via a rear axle 132. Rear axle 132 may be a singlecontinuous shaft in some embodiments, or may be split into two axles ina bi-axle configuration, wherein the axle is interposed with a reardifferential 121. In the bi-axle configuration, a first rear axle may bepositioned between the rear differential 121 and the right rear wheel101 and a second rear axle may be positioned between the reardifferential 121 and the left rear wheel 102. The rear differential isalso attached to rear drive shaft 131. The rear differential may serveseveral purposes, including allowing different relative rotationalspeeds between wheels 101 and 102 and transferring rotation (and power)from a single direction of drive shaft 131 into two perpendiculardirections of rear axle 132, as seen in FIG. 1. For example, if thevehicle is turning in the left direction, then the inboard wheel (wheel102) may rotate at a lower speed than the rotation of the outboard wheel(wheel 101). As such, rear differential 121 may allow the two wheels torotate at different speeds in order to avoid slipping between the wheelof the vehicle and a road that the vehicle is traveling across during aturn.

For operation of the aforementioned 4WD mode, wherein the front wheelsare driven in addition to the nominally-powered rear wheels, a system isprovided to transfer power to the front of the vehicle. A transfer case140 may be positioned near the output of transmission 115, the transfercase 140 may be configured to direct a portion of power from engine 110to a front drive shaft 133. In one embodiment, the transfer case 140 mayutilize a chain to transfer a portion of power from rear drive shaft 131to front drive shaft 133. In a similar fashion to the rear drive system,for the front drive shaft 133 connects to a front differential 122. Thefront differential 122 may be substantially the same as reardifferential 121, in that the front differential 122 allows relativerotational speeds of two wheels. As such, a front axle 134, which may bedivided into two axles of a bi-axle system, may be attached todifferential 122 on one end and to their respective front left wheel 104and front right wheel 103. In this configuration, drive power from frontdrive shaft 133 may be transferred through front differential 122 and towheels 103 and 104 via front axle 134. Since transfer case 140 allowspower to be outputted to both the front and rear axles, the 4WD mode mayallow all four wheels to be powered simultaneously. Said another way,when the vehicle is in the 4WD mode, both the front wheels 103 and 104and back wheels 101 and 102 may be driven.

For switching between 4WD and 2WD in the example of FIG. 1, a system isneeded that selectively engages and disengages power input to the frontwheels. As such, a disconnect 150 may be provided on front drive shaft133, effectively dividing the shaft into two separate lengths.Disconnects may be used in vehicles with more than one drivetrain modeand enable engaging or disengaging two separate input components, suchas wheel hubs, axles, and drive shafts. In the present example as seenin FIG. 1, disconnect 150 is positioned on front drive shaft 133. Inother vehicle systems, disconnect 150 may be placed in a variety oflocations, including on front axle 134. The disconnect 150 may bepositioned on an output of a transmission, and/or positioned at a powertransfer unit (PTU) to enable engagement and disengagement of the PTUshaft output. Furthermore, in some embodiments, multiple disconnects maybe provided, each of the multiple disconnects fixed to a wheel hub ofwheels 103 and 104. Depending on the particular location of thedisconnect, various names are given, including wheel end disconnect andcenter axle disconnect. In the present example, disconnect 150 mayselectively connect and disconnect two lengths of shaft 133 via a systemof gears, control mechanisms, and other structure, as described later inmore detail.

During the 2WD mode when power is only provided to rear wheels 101 and102, an input command may cause disconnect 150 to disengage fixedrotation between the two lengths of shaft 133, thereby providing nopower to front axle 134 as well as wheels 103 and 104. As such, mostpower provided by engine 110 can be directed into rear drive shaft 131with a relatively smaller amount of power diverted through transfer case140 and into the length of shaft 133 connected to the disconnect. Inother words, while disengaged, front wheels 103 and 104 may rotatefreely without receiving tractive power from the engine. Also, therotation of wheels 103 and 104 along with the rotation of axle 134 andthe portion of shaft 133 disposed in front of disconnect 150 (asdirected by the arrow in FIG. 1) does not affect the rotation of therest of the drivetrain. Specifically, since disconnect 150 separates thetwo portions of shaft 133 located to the front and rear of thedisconnect, rotation of the two lengths do not affect each other becausethey are separated (disengaged).

During the 4WD mode when power is provided to all four wheels, an inputcommand may cause disconnect 150 to engage fixed rotation between thetwo lengths of shaft 133, thereby providing power to all of shaft 133 aswell as axle 134. In the current example, fixed rotation may be causedby engagement between a series of gears and/or splined shafts thatallows the shafts on either end of disconnect 150 to rotate as asubstantially single unit. During this operating mode, power from engine110 power may be diverted substantially equally (or in otherembodiments, non-equally) to wheels 101, 102, 103, and 104. It is notedthat other drive modes are possible with the addition, change, and/orremoval of components while still conforming to the scope of thisdisclosure.

Additionally, the powertrain 100 may include a motorized disconnect 160positioned at one or more wheel ends to engage and disengage individualwheels with a corresponding axle (e.g., front axle 134 and/or rear axle132). This type of disconnect may be referred to herein as a wheel enddisconnect. The motorized disconnect 160 may alternately be positionedon one or both of the front axle 134 and the rear axle 132. Further, themotorized disconnect 160 may be positioned on either side of the frontdifferential 122 and/or the rear differential 121. For example, in oneembodiment, there may be a motorized disconnect 160 positioned on eachside (e.g., both sides) of the front differential 122 on the front axle134. Additionally, or alternatively, there may be a motorized disconnect160 positioned on each side (e.g., both sides) of the rear differential121 along the rear axle 132. In this way, the vehicle powertrain 100 mayinclude a dual-disconnecting differential system. The type of disconnectpositioned along the front or rear axles proximate to the front or reardifferentials may be referred to herein as a center disconnect, asdescribed further below with reference to FIGS. 18-27. The motorizeddisconnect described below may be used in one or more of the positionsof the motorized disconnect 160 shown in FIG. 1.

As previously mentioned, some disconnects may be powered by vacuumdiverted from the engine, such as engine 110 of FIG. 1. However, theinventors herein have recognized that vacuum may not be readilyavailable or the vacuum power may undesirably fluctuate, therebyresulting in decreased disconnect control. Thus, alternate power sourcesmay be utilized that provide simpler and more compact disconnectdesigns. As such, the inventors herein have proposed a motorizeddisconnect that is actuated by electric power from a motor located onthe disconnect system. Electric power may be constantly maintained(without fluctuation) and may not require running vacuum linesthroughout the vehicle, thereby increasing the reliability of electricpower over vacuum power. First, a description of the various componentsof the proposed motorized disconnect will be given, followed by adescription of the operation of the disconnect including an examplecontrol scheme.

FIG. 2 shows an exploded view 205, as well as a first assembly view 201and second assembly view 203, of a motorized disconnect assembly 200(referred to herein as disconnect 200). The first assembly view 201 andsecond assembly view 203 are oppositely facing views of the assembleddisconnect 200. Disconnect 200 comprises a generally circular shape witha shifter structure 230 and a control assembly 250, the control assembly250 attached to the outside of the shifter structure 230. For example,the control assembly 250 may be coupled to a single side (e.g., topside) of an outside surface of the shifter structure 230. In otherembodiments, the control assembly 250 may be coupled at another positionalong the outside surface of the shifter structure 230 (such as thebottom side). The top side and bottom side of the shifter structure 230may be defined with respect to a surface on which a vehicle in which thedisconnect 200 is installed sits.

As seen in the exploded view 205 of disconnect 200, control assembly 250includes an electric motor 251. The electric motor 251 turns an outputshaft that is equipped with a worm 253 for use in a worm drive. It isnoted here that motor 251 may only rotate in a single direction during aseries of shifting modes without the ability to reverse directions.Thus, the driving direction of the motor 251 may not change during aperiod of time. This feature is explained in more detail later.Furthermore, control assembly 250 includes a controller 255 (e.g., hubcontroller) which may be configured to operate disconnect 200 whilecommunicating with vehicle systems and controllers external todisconnect 200. It is noted that controller 255 is separate from a mainvehicle controller or other similar devices of the vehicle. However, thecontroller 255 may communicate with and receive commands from a vehicleor engine controller. Either external or attached adjacent to controller255, a magnetic bi-polar sensor may be positioned. As explained furtherbelow, magnets positioned around the circumference of shifter assembly270 may rotate with the shifter assembly 270 to align with the bi-polarsensor such that the sensor can be triggered by one of the magnetswithin a sensing range. Finally, a cap 258 may enclose the controller255 and motor 251 (with the worm 253) to form the shape of controlassembly 250.

Shifter structure 230 comprises a generally circular and ring-like shapefor the purpose of engaging (and disengaging) two generally circularinput components, such as shafts or axles. As shown in FIG. 2, thedisconnect 200 engages and disengages a rotatable, first shaft 207 and arotatable, second shaft 209. In this example, the input components(e.g., first shaft 207 and second shaft 209) are input into disconnect200 from both ends along the axial direction, as shown by the axialarrow 211 in FIG. 2. For example, a first input component (e.g., firstshaft 207) may be positioned adjacent to a first end of the disconnect200 and a second input component (e.g., second shaft 209) may bepositioned adjacent to a second end of the disconnect 200, the first endopposite the second end with respect to the axial direction. A housing232 is shown in FIG. 2 that provides an outer structure for protectingthe internal components of disconnect 200. The housing 232 may aid inpreventing dust and other contaminants from interfering with thefunction of the disconnect 200. A worm gear 234 is located insidehousing 232 and is positioned to engage with worm 253 in order toprovide rotation of worm gear 234 upon powering worm 253 via motor 251.The combination of worm 253 and worm gear 234 is also referred to as theworm drive. Rotation of the worm 253 (activated by motor 251) causesrotation of the worm gear 234. Particularly, worm gear 234 rotates aboutan axis parallel to the axial direction shown in FIG. 2 while worm 253rotates about an axis perpendicular to the axial direction. In otherwords, the axes of rotation of worm 253 and worm gear 234 areperpendicular. Further, the axis of rotation of the worm gear 234 isparallel to a rotational axis 213 of the disconnect 200, where therotation axis 213 is also a rotational axis of the first shaft 207 andsecond shaft 209.

A shifter assembly 270 is also located in housing 232 and provides theshifting motion that defines the operation of disconnect 200, that is,selectively connecting and disconnecting two rotating components (suchas shafts). A pin 236 is located inside housing 232 and is positioned tocouple the worm gear 234 to the housing 232. Also, a cam guide (e.g.,may also be referred to herein as a fixed cam guide or a fixed guide)237 is fixed inside the housing. Two additional fixed cam guides arepositioned similarly to cam guide 237, along the inside of the housing(blocked from view in FIG. 2). The additional fixed cam guides are alsofixed inside the housing so that none of the cam guides (including camguide 237) move relative to movement of the shifter assembly 270). Camguide 237 and the two additional fixed cam guides are stationary guidesand may be part of the same material as housing 232. A sealed end ofhousing 232 is at least partially covered by a seal 233. A shaft oraxle, such as first shaft 207, can be inserted through the center ofseal 233, where the seal 233 may be sized to provide a tight connectionbetween the seal and shaft. The tight connection may substantiallyprevent debris from entering the inside of housing 232 while stillallowing the shaft to rotate and the seal 233 to remain stationary andattached to the housing 232. The sealed end of housing 232 that includesseal 233 may enclose the first shaft 207 (first input component). A camkeeper 235 is located adjacent to an axial-facing surface of the shifterassembly 270, where the cam keeper includes a holding tab that can beinserted into a groove formed in the housing such that the keeper isheld stationary relative to housing 232 (without rotating). Shifterassembly 270 may be generally circular in shape with a central axis thatis parallel to the axial direction and collinear with the central axesof other components, such as seal 233, cam keeper 235, and housing 232.Furthermore, cam keeper 235 includes three fixed guides (e.g., fixed camguides) 238 that are stationary and positioned to protrude from the camkeeper towards shifter assembly 270. Only one cam guide 238 is visiblein FIG. 2. Finally, a retaining ring 239 (e.g., lock ring) may bepositioned outside the cam keeper 235 to hold the other componentsinside housing 232 and reduce undesired movement during vehicleoperation. The end of housing 232 opposite to the sealed end containingseal 233 is located in the more positive axial direction and includescam keeper 235 and retaining ring 239, as seen in the exploded view 205of FIG. 2. The opposite end of housing 232 may enclose the second shaft209 (second input component).

FIG. 3 shows an exploded view 301, an assembly view 303, a top view 304,a side view 305, and a sectional view 307 (sectional view 307 is takenalong section B-B, as shown in side view 305) of shifter assembly 270 ofFIG. 2. The shifter assembly includes a shifter gear 310 that forms theoutside shape (e.g., outer portion) of the shifter assembly 270. Theouter surface of shifter gear 310 is covered by a non-planar gear track315 that oscillates between the two ends of the shifter gear 310, thetwo ends being first end 395 and second end 396. The two ends 395 and396 are located axially on either end of shifter gear 310, as shown intop view 304. The gear track 315 circumscribes the outer surface ofshifter gear 310 without following the linear profile of the two ends.Said another way, the gear track 315 is continuous around an outercircumference of the shifter gear 310, the gear track 315 having asubstantially sinusoidal path as it travels around the outercircumference of the shifter gear 310. Additionally, the gear track 315may pass both above a below a vertical centerline of the shifter gear310, the vertical centerline perpendicular to the axial direction (e.g.,perpendicular to the axis of rotation of the shifter gear 310, where theaxis of rotation of the shifter gear 310 is the rotational axis 213 ofthe disconnect 200).

Shifter assembly 270 also includes a clutch ring 330 that is positionedon the inner surface of shifter gear 310. The clutch ring 330 includesgear teeth that may mesh with the gear teeth of an external shaft oraxle. The clutch ring 330 includes an inner surface and an outersurface, the inner surface including the gear teeth of the clutch ring330. An outer diameter of the clutch ring 330 may be smaller than aninner diameter of the shifter gear 310 such that the clutch ring 330fits within the shifter gear 310. Also, the clutch ring 330, whilelocated inside shifter gear 310, is free to rotate at a different ratethan shifter gear 310 and can rotate while the shifter gear 310 isstationary. However, clutch ring 330 is constrained to move axially withthe shifter gear (and shifter assembly 270). A first washer 320 islocated on one side of shifter gear 310 while a second washer 350 islocated on the opposite side of shifter gear 310, adjacent to clutchring 330. Lastly, two springs 340 are included in the shifter assembly,with one spring located on either end of the shifter assembly, as seenin FIG. 3. As one example, the two springs 340 may be finger springs.For example, as shown in FIG. 3, each spring 340 contains three flexiblearms that bend to provide the flexible, reversible force of the springs.However, a different type of spring other than a finger spring may beused for springs 340. Springs 340, along with washers 320 and 350, mayconstrain clutch ring 330 to move axially with the shifter assembly 270.As shown in FIG. 3, only a single washer (e.g., washer 320 or washer350) is positioned between the shifter assembly 270 and one of thesprings 340. A number of rivets 360 may be inserted through thecomponents of the shifter assembly in order to hold the shifter assemblytogether as a single unit.

The oscillations (e.g., undulations) of gear track 315 complete multiplecycles around the periphery of shifter gear 310. A complete cycle isdefined as the length of gear track 315 that oscillates from a pointadjacent to first end 395, away towards a point adjacent to second end396, and finishes at another point adjacent to first end 395. Theorientation of shifter assembly 270 with gear track 315 shows onecomplete cycle of the gear track. The oscillations of gear track 315 maybe continuously curved (sinusoidal) in some embodiments, while in otherembodiments the gear track 315 may include inclined, generally linearramps joined by flat, linear sections. Other gear track shapes may bepossible that complete multiple cycles around the periphery of shiftergear 310. Gear track 315 may be in contact with worm gear 234 of FIG. 2such that power from worm gear 234 provided by motor 251 is transmittedinto gear track 315 to cause rotation of shifter assembly 270. Morespecifically, teeth of the worm gear 234 may mate and interlock withteeth of the gear track 315. As such, rotation of the worm gear 234causes rotation of the gear track 315 and subsequently the shifterassembly 270. In addition to providing rotation, shifter assembly 270may move linearly in the axial direction as shown by the axial arrow 211in FIG. 3. Specifically, shifter assembly 270 may move back and forthalong the axial direction relative to the stationary housing 232 withthe attached control assembly 250. Housing 232 may be fixed to anexternal stationary vehicle component, as outlined below with regard toFIG. 4.

Rotational and axial movement of shifter assembly 270 is actuated byworm gear 234 engaging with gear track 315. As seen in FIG. 3, geartrack 315 protrudes radially away from shifter gear 310, forming a camprofile 318 which may be defined as the surfaces on either side of thegear teeth of gear track 315. More specifically, the gear track 315extends outwardly away from the outer surface of the shifter gear 310(in a direction perpendicular to the rotational axis of the shifterassembly 270). Fixed cam guides 237 contact cam profile 318 on one sideof shifter gear 310 and fixed cam guides 238 contact the cam profile onthe opposite side of shifter gear 310. In this way, gear track 315 iseffectively trapped (e.g., disposed) between the fixed cam guides (e.g.,fixed guides) 237 and 238. Therefore, as shifter assembly 270 rotates,fixed cam guides 237 and 238 slide against cam profile 318, therebycausing the shifter assembly to move axially.

In one example, axial cam profile 318 may be divided into three equalportions, where each portion includes a 4×4 and a 4×2 position alongwith cam ramps in between the positions. In particular, the three equalportions form three complete cycles of gear track 315, wherein the 4×4and 4×2 positions are the points closest to first end 395 and second end396 of shifter gear 310, respectively. Correspondingly, in this example,gear track 315 also contains three equal portions identical to the threeequal portions of axial cam profile 318. Therefore, as motor 251operates worm 253 and worm gear 234 in a single or first direction, gearmeshing between worm gear 234 and gear track 315 may cause rotation andaxial movement of shifter assembly 270. In this way, motor 251 may bedriven in the single direction during shifts to 4×2 and 4×4 modes. Thespinning direction of motor 251 may be reversed to a second directionwhen vehicle direction changes such that the first rotating componentalso changes direction. It may be desirable to rotate shifter assembly270 in the same direction as the rotation of the powered, first rotatingcomponent. As such, when vehicle moving direction changes, motor 251 mayalso change direction. In this way, the single or first spinningdirection of motor 251 may be maintained as long as the vehicle ismoving in a corresponding direction. In a similar fashion, as explainedin further detail later, the spinning direction of motor 251 may dependon if disconnect assembly 200 is placed on the left or right side of thevehicle, such as near wheels 103 or 104.

Springs 340 shown in FIG. 3 are attached to either side of shifter gear310 and aid in holding clutch ring 330 within the shifter assembly. Forexample, during a shift to the 4×4 position, if the teeth of clutch ring330 are not aligned with the mating teeth of an external rotatingcomponent (e.g., a shaft or an axle), then the springs will deflect toallow clutch ring 330 to remain axially stationary while the rest ofshifter assembly 270 moves in the axial direction toward the externalrotating component. As clutch ring 330 continues to rotate and alignswith the mating teeth of the external component, then springs 340 mayforce the clutch ring into the desired position within shifter gear 310.During this example, axial movement of the clutch ring 330 occurs afteraxial movement of the shifter assembly 270 upon alignment of the teethof the clutch ring and second shaft.

When a shift from 4×4 to 4×2 or vice versa is commanded by an externalcontroller, a signal may be sent to controller 255, which then commandsmotor 251 to actuate the worm drive. In particular, controller 255 maycontain computer-readable instructions stored in non-transitory memoryfor adjusting the shifter assembly based on the request from the controlsystem external to the motorized disconnect assembly. As shifter gear310 begins to rotate (via the worm drive) and moves axially as camprofile 318 is pushed by fixed cam guides 237 or 238, clutch ring 330may resist the axial movement due to friction in the clutch teeth. Ashifting force will act on clutch ring 330 as the rest of shifterassembly 270 attempts to move axially. As the clutch ring rotates, sinceit is connected to an external rotating component such as an axle, atorque may be generated by the clutch ring and transmitted into the restof shifter assembly 270. This torque may cause shifter assembly 270 torotate, thereby adding to the torque provided by motor 251 andincreasing shift speed as shifter assembly 270 rotates and moves axiallyto its other position.

For general operation of the motorized disconnect seen in FIGS. 2 and 3,and in particular operation of shifter assembly 270, the vehicle isinitially in a first drive mode. In this case, the first drive mode is2WD or 4×2 which corresponds to the disconnect being in a disconnectedposition wherein the two input components are not connected viadisconnect 200. A second drive mode may be 4WD or 4×4, which correspondsto the disconnect being in a connected position wherein the two inputcomponents are engaged via disconnect 200 and rotation of one of thecomponents corresponds to rotation of the other component. Specifically,when clutch ring 330 is connected to only one of the input components,the vehicle is in the 4×2 mode. Alternatively, when the clutch ring isconnected to both the input components, such as two shafts, the vehicleis in the 4×4 mode. In this way, as shifter assembly 270 moves axiallyby an amount determined by the motor and worm drive, clutch ring 330also moves axially either engaging or disengaging the two rotatingcomponents. Upon detection that the shifter assembly 270 is in therequested 4×4 or 4×2 mode, controller 255 may turn off the motor.

In one example operation scheme for selectively engaging two rotatingcomponents (shafts), the vehicle may initially be in the first mode(2WD). During this mode, shifter assembly 270 may be held in a firstposition. The first position may locate the shifter assembly in aposition closer to seal 233, or in the negative axial direction as shownby the arrow 211 in FIG. 3. In this first position, a first shaft 207may be engaged with the shifter assembly, in particular with clutch ring330 while a second shaft 209 is not coupled to clutch ring 330. Then, acommand may be issued by a vehicle controller to shift from the firstmode (2WD) and to the second mode (4WD). During shifting to the secondmode, worm gear 234 may be driven by worm 253 powered by motor 251 todrive gear track 315. As seen in FIG. 3, the gear track 315 oscillatesbetween the first and second ends (sides) 395 and 396, which causes theshifter assembly to slide against fixed cam guides 237 and 238, therebymoving the shifter assembly in a first axial direction (as shown by thearrow 211 in FIG. 2) to a second position where shifter assembly 270 isengaged with both the first shaft and the second shaft. Said anotherway, the teeth of the clutch ring 330 may be engaged with correspondingteeth of both the first shaft 207 and the second shaft 209. The secondposition may be located in a more positive axial direction (defined bythe axial direction arrow in FIG. 2) than the first position, such thatshifter assembly 270 is farther away from seal 233 in the secondposition than in the first position. Subsequently, a command may beissued by the vehicle controller to shift back to the first mode (2WD).As such, the motor may continue driving the worm gear in the samedirection, thereby moving the shifter assembly in a second axialdirection (the negative axial direction of FIG. 2, opposite of thearrow) until the shifter assembly reaches the first position in whichthe second shaft is again disengaged from the clutch ring 330.

In some embodiments, an additional, multi-plate clutch may be coupled inseries with the shifter assembly 270 including the clutch ring 330. Asone example, the multi-plate clutch (which may also be referred to as afriction clutch) may include a set of wedge plates rotationally coupledto one of the first and second shafts 207 and 209 and a set of clutchplates rotationally coupled to the other one of the first and secondshafts 207 and 209. A pressure plate (e.g., piston plate) may compressthe wedge and friction plates to synchronize the speeds between thefirst and second shafts 207 and 209. The clutch ring 330 of the shifterassembly 270 may then be used as a locking clutch to lock the first andsecond shafts 207 and 209 to one another, thereby fully engaging the twoshafts for complete torque transfer between the two shafts. It should benoted that the multi-plate clutch described above may be included inseries with any one of the motorized disconnect assemblies describedherein.

FIG. 4 shows a front view 401 and cross-sectional view 403, taken alongsection A-A of front view 401, of the motorized disconnect 200. From thefront and cross-sectional views, shifter assembly 270 is visible alongwith the teeth of clutch ring 330. Furthermore, disconnect 200 mayinclude one or more mounting brackets 450, each containing a hole forinserting screws, bolts, or other suitable fasteners. With mountingbrackets 450, the motorized disconnect can be mounted to a variety ofstationary vehicle components to securely hold the disconnect in place.For example, if disconnect 200 were placed at the wheel ends of avehicle, such as near wheel 103 of FIG. 1, then brackets 450 may besecured to the knuckle of the wheel, or other non-rotating componentthat holds the wheel in place. In alternate embodiments, the disconnect200 may not include brackets 450 and/or may include an altered housingfor mounting the disconnect to an alternate vehicle location, such asalong a front or rear axle, as described further below.

FIG. 5 shows a front view 501, top view 503, and side view 505 ofmotorized disconnect 200. As seen in FIG. 5, control assembly 250 may beintegrally formed with housing 232 of shifter structure 230 such thathousing 232 extends as a single piece to contain the components ofcontrol assembly 250. In other embodiments, control assembly 250 may beremovably fixed to shifter structure 230 via removable fasteners suchthat the control assembly can be easily unattached from the rest of thedisconnect. In this way, replacement of parts of control assembly 250can be easily replaced without disassembling the entire disconnect.Replaceable parts may include motor 251, worm 253, and controller 255.

As mentioned previously, disconnect 200 includes an on-board controller255 that may be configured to drive motor 251, among other functions.Furthermore, a magnetic bi-polar sensor may be located inside controlassembly 250 or adjacent to assembly 250 inside shifter structure 230.The bi-polar sensor may be coupled to (and/or incorporated as part of)controller 255 and configured to send and receive signals with thecontroller. The purpose of the bi-polar sensor may be to determine theposition of shifter assembly 270, that is, whether or not the shifterassembly is in the 4×4 (2WD) or 4×4 (4WD) position. Magnets may beplaced around the periphery of shifter assembly 270 with alternatingpolarities such that bi-polar assembly can differentiate between thedifferent magnets in order to determine shift position. For example, anorth magnetic polarity may correspond to 4×2 positions whereas a southmagnetic polarity may correspond to 4×4 positions.

FIG. 6 shows a simplified diagram 600 of the operation of a bi-polarsensor 620 for determining the shift position of shifter assembly 270.An oscillating cam profile 318 is displayed in FIG. 6, the same camprofile as previously described above with reference to FIG. 3. Toreiterate, cam profile 318 is formed by gear track 315 shifting betweenthe two end faces of shifter gear 310. While bi-polar sensor 620 may bepositioned in a stationary manner in control assembly 250, six magnets602 may be placed in shifter gear 310 near cam profile 318 and geartrack 315. For example, the six magnets 602 may be placed directly oncam profile 318 at the intersection where gear track 315 protrudes fromshifter gear 310 around the circumference of shifter gear 310. In thiscase, six magnets 602 are used since cam profile 318 (and gear track315) completes three full cycles around the periphery of shifter gear310. Furthermore, in this example, magnets with a north (N) polarity mayalign with the 4×2 positions of cam profile 318 while magnets with asouth (S) polarity may align with the 4×4 positions of cam profile 318.Bi-polar sensor 620 may be placed near shifter gear 310 in order todetect the six magnets 602. Since the magnetic field produced by each ofthe magnets can be detected by bi-polar sensor 620 from a distance, aspace may be maintained between the sensor and the magnets, therebyreducing wear of the sensor and magnets. It is noted that the number ofmagnets may be even to allow for an equal number of 4×2 and 4×4positions on cam profile 318.

As shifter gear 310 (and shifter assembly 270) rotates, the magnetsalternatingly pass in front of bi-polar sensor 620 in the shiftingdirection shown in FIG. 6 at 604. Only one shifting direction is shownin FIG. 6 since motor 251 may spin in a single direction during ashifting operation, as previously explained. In the position shown inFIG. 6, the north magnet may be sensed by sensor 620 and a signal sentto controller 255, signifying that the shifter assembly is currently ina 4×2 position. Next, as a shifting action occurs and cam profile 318moves, once the subsequent magnet with a south polarity passes in frontof sensor 620, a signal may be sent to controller 255. Upon receivingthe signal, the controller may issue a command to motor 251 to stoprotation of shifter assembly 270, thereby holding the assembly in thedetected 4×4 position corresponding to the southern-polarity magnet. Inthis way, the controller 255 may activate and deactivate the motor 251based on the position of the shifter assembly 270 as determined by apole of the magnet proximate to (e.g., closest to) the bi-polar sensor620.

FIG. 7 shows a flow chart for operation of the motorized disconnectaccording to one embodiment of the present disclosure. To reiterate, the4×2 (2WD) mode corresponds to the position where shifter assembly 270engages only one of two shafts while the 4×4 (4WD) mode corresponds tothe position where shifter assembly 270 engages both of the shafts,thereby coupling the two shafts together. For ease of understanding,reference will be made to components and description presented withregards to the previous figures. FIG. 7 displays a method 700 forcontrolling movement and shifting functions of the disconnect, such asdisconnect 200 and associated components of FIGS. 2-5. Instructions forcarrying out method 700 may be stored in a memory of a controller, suchas controller 255 shown in FIG. 2.

First, at 701, a series of initialization operations may be performed bycontroller 255. The initialization operations may include calibration ofthe bi-polar sensor attached to the controller along with establishingcommunication between the controller and an external controller, such asa main vehicle controller. Next, at 702, an input command may be sent tocontroller 255 located on disconnect 200 as previously described. Theinput command may be an operator (i.e. driver) request for a change from4×2 to 4×4 or vice versa. In this system, the command may be sentthrough a main vehicle controller before being sent to controller 255.As such, the method at 702 may include receiving an input command fromthe main vehicle controller. Upon receiving the shift command, at 703 itmay be determined if 4×4 operation is requested or not. If 4×4 operationis requested, then the process proceeds to 704. Alternatively, if 4×4operation is not requested, then the process proceeds to 708, which isexplained further below. At 704 it may be determined if shifter gear 310is at the 4×4 position. Referring back to the discussion of bi-polarsensor 620 of FIG. 6, the sensor may detect if a north or south magnetis positioned in front of (or within a reading range of) the sensor,thereby allowing controller 255 to determine if the shifter gear is at a4×4 position. If the shifter gear is not at the 4×4 position, then at705 the motor may be turned on in order to rotate and axially move theshifter assembly until cam profile 318 moves enough such that a magnetcorresponding with the 4×4 position is reached. Once the shifter gear isin the 4×4 position, then at 706 the motor may be turned off in order tohold the desired 4×4 position. Finally, at 707, the controller mayoutput a 4×4 feedback signal to the main vehicle controller, therebysignifying completion of the shift to 4WD.

Returning to 703, if 4×4 operation is not requested, then the processproceeds to 708. Subsequently, at 708 the method may include determiningif 4×2 operation is requested. If 4×2 operation is not requested (as thevehicle input command of 702), then at 713 an invalid input is detectedby the controller. In this situation, at 714 an output fault code may besent by controller 255 to the external vehicle controller and theprocess ends. This branch of operation (including steps 713 and 714)allows controller 255 to detect invalid input commands and issue a faultcode without allowing the invalid commands to disrupt operation of thecontroller and the disconnect operation. Alternatively, at 708 if 4×2operation is detected, then at 709 it may be determined if shifter gear310 is at the 4×2 position. If the shifter gear is not at the 4×2position, then at 710 the motor may be turned on in order to rotate andaxially move the shifter assembly until cam profile 318 moves enoughsuch that a magnet corresponding to the 4×4 position is reached. Forexample, referring to FIG. 6, if the shifter gear is at the 4×4 positioncorresponding to a south magnet initially, then the motor may be turnedon to move the shifter gear (along with the cam profile) until a northmagnet is positioned in front of the bi-polar sensor, signifying thatthe shifter gear is at a 4×2 position. Once the 4×4 position is reached,then at 711 the motor may be turned off to hold the desired 4×2position. Finally, at 712, controller 255 may output a 4×2 feedbacksignal to the main vehicle controller, thereby signifying completion ofthe shift to 2WD.

In this way, method 700 involves receiving a request at hub controller255 of control assembly 250 from the vehicle controller in order toadjust shifter assembly 270 into a requested position, such as 4×2 or4×4 positions corresponding to a connected position connecting tworotatable shafts (4×4) or a disconnected position not connecting the tworotatable shafts (4×2). Also, a current position of the shifter assemblymay be determined based on an output of magnetic position sensor 620,which may be coupled to control assembly 250. Shifter assembly 270 mayinclude a plurality of magnets disposed around the circumference of theshifter assembly. The magnetic position sensor may output a positionsignal based on which of the plurality of magnets is closest to theposition sensor, thereby determining whether the current position is theconnected (4×4) or disconnected (4×2) position. Finally, electric motor251 may be activated to drive worm gear 234 to rotate in a singledirection and axially adjust the shifter assembly into the requestedposition (4×4 or 4×2) when the current position is different than therequested position. As explained previously, if the requested (desired)position is the same as the current position of the shifter assembly,then no further action is required.

It is understood that shifting method 700 for commanding shiftingoperation of disconnect 200 via electronic control by controller 255 maybe executed according to a number of different control schemes. Thescheme shown in FIG. 7 is one example that shows how the disconnect canbe controlled to achieve desired shifting operation. Other controlschemes may be implemented while maintaining the general operation ofthe disconnect according to the scope of the present disclosure.

FIG. 8 shows a simple schematic 800 of controller 255 of FIG. 2according to one embodiment of the present disclosure. Controller 255may include a microcontroller unit 810 that inputs and outputs signalsof motorized disconnect 200, communicates with an external vehiclecontroller, and performs the processing necessary to operate shiftingoperations. For example, the microcontroller unit 810 may processincoming data (e.g., received signals) and perform the necessaryshifting operations in combination with the various actuators, sensors,and disconnect components described above. In the arrangement displayedin FIG. 8, a vehicle input command signal 720 may be sent tomicrocontroller unit 810. Input command signal 720 may be sent by theexternal vehicle controller (external to controller 255), and include acommand for 4×4 or 4×2 shifting. As an example, the vehicle mayoriginally be in a 4×2 mode (2WD mode) and an operator may desire toswitch to a 4×4 mode (4WD mode). Upon the operator input, the vehiclecontroller may send a command 720 to microcontroller unit 810, thecommand including a request to shift to a 4×4 mode. Upon receiving andprocessing the input command, microcontroller unit 810 may accordinglyturn on motor 251 to engage the worm drive and move the shifter assemblyinto the desired position. Upon completion of a shifting event, anoutput feedback signal 730 may be sent to the external vehiclecontroller. It is noted that when motor 251 is turned off uponcompletion of the desired shift, a dynamic braking action may be presentsince the motor is grounded, as seen in FIG. 8. This dynamic brakingallows the shifter assembly to remain stationary while only the clutchring 330 is allowed to rotate. Furthermore, the worm drive attached tomotor 251 may substantially prevent backwards driving of the motor 251and shifter assembly 270. Particularly, motor 251 may not be drivenbackwards by axle friction torque acting against shifter assembly 270,thereby allowing the shifter assembly 270 to remain stationary whilemotor 251 is turned off.

Furthermore, controller 255 may be a smart controller, in that itoperates the motor 251 according to a closed loop scheme as opposed toan open loop, time-based scheme. Furthermore, as controller 255 isself-contained and located on disconnect 200, vehicle cost may bereduced as the vehicle controller does not have to incorporate theprocessing instructions needed to operate disconnect 200. The bi-polarsensor 620 may send a signal to the microcontroller unit 810 including acurrent (e.g., actual) position of the shifter assembly. For example,the signal received at the microcontroller unit 810 from the bi-polarsensor 620 may be feedback of whether the shifter assembly is in a 4×4,connected mode or a 4×2, disconnected mode. As described above, the 4×4and 4×2 driving modes may correspond to a south-pole magnetic signal anda north-pole magnetic signal, respectively. The signal sent from themicrocontroller 810 and to the motor 251 may then be based on both theposition feedback from the bi-polar sensor (e.g., current position ofthe shifter assembly) and the vehicle input command signal 720 (e.g.,requested position of the shifter assembly).

In this way, motorized disconnect assembly 200 provides a compact devicefor selectively engaging two rotating components. Shifter structure 230contains shifter assembly 270 and other components for shifting betweentwo different drive modes while remaining compact in design.Furthermore, control assembly 250 may be attached to the periphery ofshifter structure 230 while maintaining the compact design sincecontroller 255 and motor 251 can be small compared to the rest of thedisconnect assembly. The worm drive for operating the shifter gear maybe more reliable than other systems since the worm drive reducesrotational speed while increasing torque by default without the need forcomplex gear boxes for gear reduction. Also, the worm drive may bequieter than other gear assemblies. For these reasons, theself-contained and compact motorized disconnect system may providebenefits not exhibited by other disconnect systems.

Additionally, the electric motor 251 required to power the shiftingaction of the disconnect assembly 200 may be contained within thehousing 232 (e.g., surrounded by and entirely encased within the housing2323) of the disconnect assembly and locally controlled by hubcontroller 255 located on-board the disconnect assembly. The hubcontroller may include the necessary instructions for receiving commandsignals from an external vehicle controller, interpret and process thosecommands, and drive the electric motor while receiving signals from oneor more sensors for determining a current operating mode of thedisconnect. As such, computing power of the external vehicle controllermay be designated for other functions while the hub controller 255 maybe dedicated to operation of the motorized disconnect assembly 200.

FIGS. 9-17 show another embodiment of the motorized disconnect assemblyin various views along with a related control scheme and electronicdiagram. For example, FIGS. 9-17 show an embodiment of the motorizeddisconnect employed as a wheel end disconnect coupled to a wheel end ofa vehicle. Many devices, methods and/or components in FIGS. 1-8 are thesame as devices, methods and/or components shown in FIGS. 9-17.Therefore, for the sake of brevity, devices, methods and components ofFIGS. 9-17, and that are included in FIGS. 1-8, are labeled the same andthe descriptions of these methods, devices and components is omitted inthe descriptions of FIGS. 9-17.

FIG. 9 shows an embodiment of a motorized disconnect assembly 900mounted to a wheel knuckle 925. Specifically, FIG. 9 shows a side view901, a sectional view 903 taken along section A-A of side view 901, anda blown-up view 905 of sectional view 903 of the motorized disconnectassembly 900 mounted to the knuckle 925. Knuckle 925 may be anintermediate structure to which the wheel and other wheel components aremounted to. For example, while on one side of knuckle 925 the wheel isattached, the other side of knuckle 925 may contain attachment featuresfor connecting to the vehicle suspension, steering system, and brakingsystem. Motorized disconnect assembly 900 may be attached to a side ofknuckle 925 for selectively disconnecting two rotating components. Inthis embodiment, the two rotating components may be an axle half shaft931 and wheel hub 934. Axle half shaft 931 may be similar to or the sameas front axle 134 of FIG. 1 divided into two axles of a bi-axle (halfshaft) system. Furthermore, while wheel hub 934 is the second rotatingcomponent in this embodiment, a coupler 937 may include gear teeth forselectively meshing with the gear teeth of clutch ring 330. Coupler 937may be rotatably attached to wheel hub 934 such that rotation of eithercoupler 937 or wheel hub 934 corresponds to the same rotation of theother component. Wheel hub 934 may be attached to knuckle 925 via wheelbearing 933. In this way, wheel hub 934 may rotate while knuckle 925remains stationary (non-rotating). For the configuration shown in FIG. 9and subsequent figures, disconnect assembly 900 may be referred to as anintegrated wheel end disconnect.

FIG. 10 shows three possible positions of motorized disconnect assembly900. More specifically, FIG. 10 shows the side view 901 of the knuckleincluding the motorized disconnect assembly 900 mounted thereto and across-section 1000 of the knuckle taken along cutting plane C-C. FIG. 10shows a series of detailed views, where the location of the detailedview is shown at 1001 in cross-section 1000. The first, 4×2 position isshown in detailed view 910 while the second, 4×4 position is shown indetailed view 912. Referring to view 910, clutch ring 330 is engagedwith only axle 931 (the first rotating component) and not engaged withwheel hub 934. During the 4×2 mode corresponding to the 4×2 position ofclutch ring 330, rotation of wheel hub 934 may be independent fromrotation of axle 931. Referring to view 912, clutch ring 330 is engagedwith the gear teeth of both axle 931 and wheel hub 934 via coupler 937.During the 4×4 mode corresponding to the 4×4 position of clutch ring330, the rate of rotation of wheel hub 934 may be substantially equal tothe rate of rotation of axle 931. Additionally, during the 4×4 modeshown in view 912, power (rotational speed and torque) from the enginemay be provided to axle 931 and transfer to wheel hub 934 via clutchring 330. The third detail view 911 shows a blocked shift position,wherein springs 340 may deflect to allow shifter assembly 270 tocomplete its shifting motion while the clutch ring 330 shift is delayed.For example, during a shift from the 4×2 to 4×4 positions, as shown indetail views 910 and 912, respectively, the gear teeth of clutch ring330 may not be aligned with the gear teeth of coupler 937. As such,shifter assembly 270 and shifter gear 310 may continue to move axiallyaccording to the worm drive while springs 340 deflect against clutchring 330. Once the gear teeth are appropriately aligned, springs 340 maypush the clutch ring 330 into its 4×4 position. In this way, shiftergear 310 may not stop abruptly and cause damage to the worm drive and/ormotor 251.

FIG. 11 shows a side view 1101, a sectional view 1103 taken alongsection J-J in side view 1101, and a detailed view 1105 from sectionalview 1103 of motorized disconnect assembly 900. In particular, anelectrical cable 958 is shown extending from control assembly 250. Cable958 may provide the electrical connection between disconnect assembly900 and the external vehicle controller for providing shifting requeststo the disconnect assembly 900. Furthermore, as shown in detailed view1105 of FIG. 11, magnetic bi-polar sensor 620 is shown attached to anarm extending from control assembly 250. Sensor 620 may be electricallyattached to hub controller 255 via the arm. In this way, sensor 620 maybe positioned in shifter structure 230 proximate to shifter assembly270. A series of magnets 961 with North and South polarizations may bepositioned along gear track 315, adjacent to cam profile 318. In oneexample configuration, sensor 620 may be positioned directly adjacent toone of the three fixed cam guides 237. In particular, sensor 620 may beattached to one side of the fixed cam guide 237 closest to controlassembly 250. Since gear track 315 is held in between correspondingstationary cam guides 237 and 238, gear track 315 (and cam profile 318)may rotate in between cam guides 237 and 238 while sensor 620 may detectif a North or South magnet 961 passes in front of the sensor 620. Inthis way, an air gap 977 may be maintained at a substantially constantwidth in between sensor 620 and magnets 961 to enable proper calibrationand function of sensor 620.

In an alternate embodiment, the cap 258 of the control assembly 250 maynot include cable 958 and may instead include a built-in receptacle fora wire harness connector to be plugged into the control assembly 250.Said another way, the cap 258 may include an electrical receptacleadapted to receive a wire harness coupled to the external vehiclecontroller for providing shifting requests to the disconnect assembly900.

FIG. 12 shows a first view 1201 and second view 1203, the first andsecond views rotated 90 degrees from one another, of control assembly250. Hub controller 255 may include circuitry and electrical componentsfor commanding several functions of motorized disconnect assembly 900.For example, a power supply 915 may be included in controller 255 forinputting electrical power to control assembly 250 in order to drivemotor 251. Furthermore, a motor driver 916 may be included in controller255 for commanding forward or reverse directionality of motor 251. Inother words, motor 251 may power an output shaft in clockwise orcounterclockwise rotational directions. A microprocessor 917 mayinterpret shifting requests received from the external vehiclecontroller via cable 958 and process those requests to send commands toother components located in controller 255. As seen in FIG. 12, magneticbi-polar sensor 620 is attached to an arm that connects to controller255. The arm may extend such that sensor 620 is adjacent to thecircumference of shifter assembly 270.

FIG. 13 shows a top view 1301, side view 1300, cross-sectional view 1302taken along section L-L in side view 1300, and a detailed view 1303 of aportion of cross-sectional view 1302 of the shifter assembly 270 outsideof shifter structure 230. Magnets 961 with North (N) and South (S)polarizations are seen in detail M and around the sides of gear track315. The polarization of magnets 961 alternates around gear track 315,each magnet corresponding to a 4×2 or 4×4 position of the shifterassembly 270. Several 981 may be placed on both ends of shifter assembly270. Furthermore, a spring 340 is visible in a collapsed or non-deformedposition.

FIG. 14 shows a top view 1401, side view 1400, and cross-sectional view1402 taken along section N-N in side view 1400 of shifter assembly 270,similar to the views seen in FIG. 13. However, springs 340 are shown intheir extended, or deformed, positions in FIG. 13. As previouslyexplained, springs 340 may deflect against clutch ring 330 as the restof shifter assembly 270 moves in the axial direction during a shiftingmotion. In such a situation, clutch ring 330 may be held stationary inthe axial direction until the gear teeth of clutch ring 330 and gearteeth of the second rotating component (coupler 937 attached to wheelhub 934) align, whereupon springs 340 may push clutch ring 330 into thesecond, 4×4 position.

FIGS. 15 and 16 show an example method 1600 for operating the disconnectassembly 900 and associated components shown in FIGS. 9-14. Method 1600may share similar steps to method 700 with the addition of determiningwhether the disconnect assembly 900 is attached to (e.g., installed on)a left or right wheel as well as whether the vehicle is traveling in theforward or backward direction. As such, motor 251 to move shifterassembly 270 to the 4×2 and 4×4 positions may be configured to rotate inboth the forward and reverse directions according to whether forward orreverse direction of the vehicle is desired or if the disconnectassembly is attached to the left or right side of the vehicle.

First, at 1501, a series of initialization operations may be performedby controller 255 similar to step 701 of method 700. Again, theinitialization operations may include calibration of the bi-polar sensorattached to the controller along with establishing communication betweenthe controller and an external controller, such as a main vehiclecontroller. Next, at 1502, an input command may be sent to controller255 located adjacent to disconnect 900. The input command may be anoperator (i.e. driver) request for a change from 4×2 to 4×4 or viceversa. In this system, the command may be sent through a main vehiclecontroller to hub controller 255 via cable 958.

Upon receiving the shift command, at 1503 the method includesdetermining if 4×4 operation is requested or not. If 4×4 operation isrequested, then the process proceeds to 1504. Alternatively, if 4×4operation is not requested, then the process proceeds to FIG. 16, whichis a continuation of method 1500. At 1504, the method includesdetermining if shifter gear 310 is at the 4×4 position. If the shiftergear 310 is not in the 4×4 position, then at 1507 the method includesdetermining if the left wheel is selected, that is, if the secondrotating component is the left wheel hub (or coupler). If the left wheelis selected, then at 1508 the controller 255 may turn on motor 251 tospin in the clockwise direction, thereby rotating shifter assembly 270in the same direction as the first rotating component (or front lefthalf shaft). Alternatively, if the right wheel is selected, thencontroller 255 may turn on motor 251 to spin in the counterclockwisedirection, thereby rotating shifter assembly 270 in the same directionas the front right half shaft. It is noted that at steps 1508 and 1509,forward vehicle motion is assumed. If the vehicle is traveling inreverse, then at 1508 the motor may spin in the counterclockwisedirection, opposite to what is shown in FIG. 15. Similarly, for reversevehicle motion, at 1509 the motor may spin in the clockwise direction.In this way, shifter assembly 270 may rotate in the same direction asthe first rotating component.

Upon operating motor 251 according to steps 1508 or 1509, then at 1504the method includes checking again if shifter gear 310 is in the 4×4position via sensing the alignment of magnets 961 in front of sensor620. Once shifter gear 310 is in the 4×4 position, then at 1505 themotor may be turned off to hold the desired4×4 position. Finally, at1506, the controller may output a 4×4 feedback signal to the mainvehicle controller, thereby signifying completion of the shift to 4WD.

Returning to 1503, if 4×4 operation is not requested, then method 1500proceeds to FIG. 16, depicting the rest of method 1500. Subsequently, at1510 the method includes determining if 4×2 operation is requested. If4×2 operation is not requested, then at 1517 an invalid input isdetected by controller 255. In this situation, at 1518 an output faultcode may be sent by controller 255 to the external vehicle controller,thereby ending the process. Alternatively, at 1510, if 4×2 operation isdetected, then at 1514 the method includes determining if the left wheelis selected, similar to step 1507. If the left wheel is selected, thenat 1515 the motor is turned on in the clockwise direction. If the leftwheel is not selected and the right wheel is instead selected, then at1516 the motor is turned on in the counterclockwise direction. Aspreviously mentioned, if the vehicle is traveling in reverse, then themotor directions at steps 1515 and 1516 may also be reversed. Once theshifter gear reaches the 4×2 position as determined by sensor 620, thenat 1512 the motor may be turned off to hold the 4×2 position andsubstantially prevent backwards driving of the motor via dynamicbraking. Finally, at 1518, controller 255 may output a 4×2 feedbacksignal to the main vehicle controller, thereby signifying completion ofthe shift to 2WD.

FIG. 17 shows another example of a simplified electrical schematic 1700of controller 255, including many of the same components shown in FIG.7. In addition to receiving the input command 720 to switch between 4×2and 4×4 modes, a second input command 750 may be received bymicrocontroller unit 810. The second input command 750 may tell unit 810whether or not the disconnect assembly controller by controller 255 islocated on the left or right side of the vehicle. Furthermore, a thirdinput command 760 may be sent to unit 810 by the external vehiclecontroller, wherein the third input command 760 may tell unit 801whether the vehicle is traveling in the forward or backward (reverse)direction. With signals 720, 750, and 760 along with the currentposition of the disconnect assembly as determined by sensor 620, motor251 may be operated accordingly. It is noted that in this example motor251 may be rotated in both a clockwise and counterclockwise directionaccording to the input signals. However, during a commanded mode such as4×4 on the left wheel in a forward direction, motor 251 may be commandedto rotate in only the appropriate direction (such as clockwise) duringthe duration of the commanded mode. In this way, motor 251 may be drivenin the one direction and held to provide dynamic braking.

The controller schematic of FIG. 17 may provide control for a simplifiedand low cost bidirectional drive wherein the motor 251 may be driven intwo directions depending on the positioning of the disconnect assemblyand direction the vehicle is traveling. In other embodiments, signals750 and 760 to determine the left/right disconnect positioning andforward/backward vehicle movement, respectively, may be replaced byadditional pin connections to microcontroller unit 810. As such, ratherthan receiving signals 750 and 760 from the external vehicle controller,sensors or other devices may be positioned adjacent to the disconnectassembly to detect the axle rotation of the vehicle in order todetermine what direction motor 251 spins. Other components may be added,changed, and/or removed from the schematic of FIG. 17 while stillconforming to the scope of this disclosure.

In this way, in addition to controlling switching between the 4×2 and4×4 positions, controller 255 may determine if the disconnect assembly900 is mounted on the left or right side of the vehicle by receiving asignal from the external vehicle controller via cable 958. Once themounting position of the disconnect assembly is determined, thencontroller 255 may instruct motor 251 to rotate in the directionmatching the direction of axle rotation while the vehicle is traveling.In a vehicle with multiple disconnect assemblies, such as one for eachof the two front wheels, the vehicle control system may instruct themotors to turn one direction for forward vehicle travel and the oppositedirection for reverse vehicle travel. As such, the external vehiclecontroller may include instructions for sending shifting requests to oneor more disconnect assemblies located at different parts of the vehicle.

Turning now to FIGS. 18-22, embodiments of a center motorized disconnect1802 positioned along a vehicle axle are shown. The center motorizeddisconnect 1802 may have similar components and function similarly tothe motorized disconnect assembly described above with reference toFIGS. 2-8. The center motorized disconnect 1802 may also operatesimilarly and include similar components as the wheel end motorizeddisconnect shown in FIGS. 9-17. However, instead of selectivelydisconnecting an axle half shaft and a wheel hub, the center motorizeddisconnect 1802 may selectively disconnect two portions of an axle(e.g., such as two portions of front axle 134 or rear axle 132 shown inFIG. 1).

For example, FIG. 18 shows a schematic 1800 of a first embodiment of thecenter motorized disconnect 1802 positioned along an axle 1804 of avehicle. For example, the axle 1804 may be a front axle or rear axle ofthe vehicle. As shown in FIG. 18, the center motorized disconnect 1802is positioned in a mid-portion of the axle 1804 and away from the wheeland tire 1818 positioned on either end of the axle 1804. The axle 1804may be coupled on either end of the axle 1804 to a half shaft 1816. Eachhalf shaft 1816 is coupled to a wheel hub 1820 with a knuckle 1824 andwheel bearing 1822 surrounding the connecting shaft between the halfshaft 1816 and wheel hub 1820. As shown in FIG. 18, the center motorizeddisconnect 1802 is positioned to one side of a differential 1806 (e.g.,may be front differential 122 or rear differential 121 shown in FIG. 1).In alternate embodiments, the center motorized disconnect may bepositioned on the opposite side of the differential 1806, as shown inFIG. 21, described further below.

The differential 1806 is directly coupled to a propeller shaft 1814. Thepropeller shaft 1814 may be part of or coupled to a front or rear driveshaft of the vehicle (e.g., such as front drive shaft 133 or rear driveshaft 131 shown in FIG. 1). As such, rotative power is translated from avehicle drive shaft to the differential 1806. The differential 1806,arranged along the axle 1804, then distributes the torque to each of thewheels coupled to the axle 1804. The differential 1806 is coupled on afirst side to a stub shaft 1812, the stub shaft 1812 part of the axle1804 and directly coupled to one of the half shafts 1816. Thedifferential 1806 is directly coupled on a second side, opposite thefirst side, to an intermediate shaft 1810 of the axle 1804.

The intermediate shaft 1810 is further coupled to the center motorizeddisconnect 1802. The center motorized disconnect 1802 is also coupled toa coupler shaft 1808, the coupler shaft 1808 directly coupled to anotherone of the half shafts 1816. As such, the center motorized disconnectmay selectively disconnect two rotating components from one another, thetwo rotating components being the coupler shaft 1808, connected to afirst wheel 1801, and the intermediate shaft 1810, coupled to thedifferential 1806 and thus the drive shaft of the vehicle through thepropeller shaft 1814.

The center motorized disconnect 1802 consists of one disconnecting unitopposed to the two units of a hub lock system which has one assembly oneach wheel. Since only one disconnecting unit is used, only one wheel(e.g., first wheel 1801) may be disconnected and the other wheel (e.g.,second wheel 1803) may remain connected (e.g., to the drive portion ofthe axle 1804). For example, the center motorized disconnect 1802 shownin FIG. 18 may disconnect the first wheel 1801 from the drivetrain whilethe second wheel 1803 remains coupled to the drivetrain. The connectedsecond wheel 1803, adjoining half shaft 1816, and stub shaft 1812 turntogether, as do the disconnected coupler shaft 1808, adjoining halfshaft 1816, and first wheel 1801. The intermediate shaft 1810 turns atthe same speed as half shaft 1816 connected to wheel 1803 and stub shaft1812, but in the opposite direction because of the differential bevelgears. Since the average speed of the intermediate shaft 1810 and stubshaft 1812 may be approximately zero, the differential carrier andpropeller shaft 1814 remain motionless. The center motorized disconnect1802 may offer benefits over the wheel end disconnect shown in FIGS.9-17, such as reduced overall size, reduced cost, simplifiedimplementation, and reduced shifting noise. Further, as shown in FIG.18, the center motorized disconnect 1802 and the differential 1806 maybe coupled to an axle housing 1826. The center motorized disconnect 1802includes an actuator 1828 for selectively engaging and disengaging thecoupled shaft 1808 and the intermediate shaft 1810, as described furtherbelow with reference to FIGS. 23-27.

FIG. 19 shows a schematic 1900 a second embodiment of the centermotorized disconnect 1802 positioned along the axle 1804 of a vehicle.As shown in FIG. 19, the axle 1804 (specifically, the intermediate shaft1810 of the axle 1804) is positioned through an engine oil pan 1902. Thecenter motorized disconnect 1802 is positioned on a first side of theengine oil pan 1902 while the differential 1812 is positioned on asecond side of the engine oil pan 1902, the second side opposite thefirst side along a length of the axle 1804.

FIG. 20 shows a schematic 2000 of a third embodiment of the centermotorized disconnect 1802 positioned along the axle 1804 of a vehicle.The third embodiment is similar to the first embodiment shown in FIG.18. However, as shown in FIG. 20, the half shafts 2002 may be longerthan the half shafts 1816 in FIG. 18. The center motorized disconnect1802 is positioned closer to the differential 1806 along theintermediate shaft 2004. As such, the intermediate shaft 2004 of FIG. 20is shorter than the intermediate shaft 1810 of FIG. 18. Further, theoverall length of axle 1804 may be shorter in FIG. 20 than in FIG. 18.In this way, the center motorized disconnect 1802 and the differential1806 may be positioned closer or farther away from one another along theaxle 1804.

FIG. 21 shows a schematic 2100 of a fourth embodiment of the centermotorized disconnect 1802 positioned along the axle 1804 of a vehicle.In the fourth embodiment, the engine oil pan 1902 is positioned on afirst side of the differential 1806 with the stub shaft 1812 runningthrough the engine oil pan 1902. The center motorized disconnect 1802 ispositioned on a second side of the differential 1806 and may disconnectthe second wheel 1803 from the drivetrain (instead of the first wheel1801, as shown in the previous FIGS. 18-20).

FIG. 22 shows a schematic 2200 of a fifth embodiment of the centermotorized disconnect 1802 positioned along the axle 1804 of the vehicle.However, in FIG. 22, the axle 1804 is a monobeam axle coupled directlyto a joint 2202 of the wheel hub 1820 and not to a half shaft. As such,the center motorized disconnect 1802 shown in FIG. 22 selectivelydisconnects the coupler shaft 1808 and intermediate shaft 1810 of themonobeam axle 1804.

Traditional center disconnect systems may move the clutch ring of thesystem with a gear motor actuator through a shift fork which slides on ashift shaft. However, this arrangement may result in higher cost, highercomplexity, and more space required to fit all the system components.Additionally, axle shaft rotation may be effectively isolated from thegear motor actuator. Therefore, the axle shaft rotation may not be usedto assist in shifting the clutch ring into engagement or disengagement.

Instead, the center motorized disconnect 1802 shown in greater detail inFIGS. 23-27 may combine the actuator, clutch ring, and shift fork into asingle compact assembly. This compact assembly may reduce cost,complexity, and the space required for the assembly along the axle.Further, the center motorized disconnect 1802 described below may usethe axle shaft rotation to assist in shifting the clutch ring intoengagement or into disengagement. As such, the rotation of the axle 1804as the vehicle moves down the road may assist in moving the gears andcams of the center motorized disconnect, thereby reducing the load onthe motor. Reduced motor load leads to an increase in shift speed and anincrease in motor durability.

FIGS. 23-27 may include similar components to those described above inFIGS. 2-8 and FIGS. 9-17. As such, similar components have been numberedsimilarly and may function as described above with reference to FIGS.2-17. Thus, the center motorized disconnect may operate similarly to asdescribed above with reference to FIGS. 2-17. FIG. 23 shows a schematic2300 of various exterior views of the center motorized disconnect 1802.Specifically, FIG. 23 includes a first side view 2301, a second sideview 2303, rotated around the rotational access of the center motorizeddisconnect 1802 from the first side view 2301, an isometric view 2305,and an end view 2307. The center motorized disconnect 1802 includes anouter housing 2306 including a base housing 2302 and cover housing 2304.The outer housing 2306 fully encloses (e.g., fully surrounds andencases) the internal components of the center motorized disconnect1802. The center motorized disconnect 1802 further includes theintermediate shaft 1810 and the coupler shaft 1808, the center motorizeddisconnect selectively disconnecting the intermediate shaft 1810 and thecoupler shaft 1808. An electrical cable 958 is also shown in FIG. 23which provides the electrical connection between the center motorizeddisconnect 1802 and the external vehicle controller for providingshifting requests to the disconnect assembly.

In one embodiment, the base housing 2302 (similar to the cap 258 shownin FIG. 2) may include a built-in receptacle for a wire hirenssconnector to be plugged into the base housing 2302 instead of includingthe electrical cable 958.

FIG. 24 shows an exploded view of the center motorized disconnect 1802,as well as a detailed view 2401 of a portion of the exploded view. Thecenter motorized disconnect 1802 includes a shifter assembly housing2406 (may be similar to housing 232 shown in FIG. 2) housing the shifterassembly 270. The shifter assembly 270 includes a shifter gear 310 (mayalso be referred to as a cam gear) including one or more magnets 961. Aclutch ring 330 is positioned inside the shifter gear 310 and bushings2402 are positioned on either side of the clutch ring 330 (the bushingsmay be similar to washers 320 and 350 shown in FIG. 3). The shifterassembly 270 further includes two springs 340. A cover cam insert 2404may be positioned proximate to the shifter assembly 270 and may operatesimilarly to the cam keeper 235 shown in FIG. 2. The center motorizeddisconnect further includes a motor 241 driving a worm 253, which inturn drives a worm gear 234. The worm 243 cannot be back driven. Inalternate embodiments, the worm 253 may be referred to as the worm gearand the worm gear 234 may be referred to as the drive gear.

A controller 255 (e.g., center disconnect controller) operates the motor251 and may communicate with a position sensor 620 for sensing theposition of the shifter gear 310 via the magnets 961. It should beappreciated that the position sensor 620 and magnets 961 comprise aswitching system. In alternate embodiments, an alternate type ofswitching system, such as a snap switch and actuation points, a contactwiper which follows an encoder, or optical switching, may be used. Thecontroller 255 is used to respond to control inputs to start and stopthe motor 251, and to run it in the correct direction. The direction ofrotation of the motor 251 may be determined from a vehicle signalindicating forward or reverse vehicle motion. As such, a forward vehiclemotion results in forward motor rotation. The motor may run in thereverse direction if the vehicle reverse signal is detected. However,the motor always runs in a direction equal to the vehicle direction andcannot switch directions unless the vehicle direction switches.

The controller 255 may also be configured to detect various types offaults and take corrective measures in response to the detected faults.A stalled motor, for example, may be detected as a fault. In oneexample, momentary reversal of the motor direction may correct thestalled motor. The controller 255 may include additional sensors suchaxle speed sensors. Signals from axle speed sensors may be used tofurther refine the shifting algorithm under certain vehicle conditions.For example, the controller 255 may not allow a mode shift (e.g., 4×4 to4×2) when the vehicle is stopped or travelling at high speeds.

In some embodiments, an additional, multi-plate clutch may be coupled inseries with the shifter assembly 270 including the clutch ring 330. Themulti-plate clutch may be configured similar to the multi-plate clutchembodiment described above with reference to FIGS. 2-3.

In this way, the technical effect of the motorized disconnect assemblyis efficiently and accurately engaging and disengaging two rotatingcomponents of a vehicle drivetrain. As explained above, the motorizeddisconnect assembly is actuatable via an electric motor instead ofvacuum, which may not be readily available in a vehicle.

FIGS. 25-27 show various cross-sectional views of the center motorizeddisconnect 1802 described above. Specifically, FIG. 25 shows a first endview 2500, a first cross-sectional view 2401 taken along section lineB-B shown in first end view 2500, and a first detailed view 2502 of aportion of the first cross-sectional view 2401 of the center motorizeddisconnect 1802. As shown in the first detailed view 2502, the clutchring is radially interior to and concentric with the shifter gear 310.FIG. 25 further shows a second end view 2503 with components removed forclarity, a second cross-sectional view 2404 taken along section line D-Dshown in second end view 2503, and a second detailed view 2505 and thirddetailed view 2506 of portions of the second detailed view 2505. Inparticular, second detailed view 2505 shows a proximity of one magnet961 to the position sensor 960, where a south pole of the magnet isproximate to the position sensor 960.

FIGS. 26-27 show a first end view 2600 of the center motorizeddisconnect 1802. Further, FIGS. 26-27 shows a first cross-sectional view2601 where the disconnect is in the 4×2 configuration, a secondcross-sectional view 2603 where the disconnect is in the 4×4configuration, and a third cross-sectional view 2605 where thedisconnect is in the blocked shift conditions, each of thecross-sectional views taken along line section G-G of first end view2600. FIG. 26 further shows a first detailed view 2602 of the disconnectin the 4×2 configuration, a second detailed view 2604 of the disconnectin the 4×4 configuration, and a third detailed view 2606 of thedisconnect in the blocked shift condition. These three configurationsmay be the similar to the shift configurations described above withreference to FIG. 10. For example, in the 4×2 configuration, the clutchring 330 is not engaged with both the intermediate shaft 1810 and thecoupler shaft 1808. In the 4×4 configuration, the clutch ring 330 isfully engaged with both the intermediate shaft 1810 and the couplershaft 1808.

Additional components not described herein may be included in the centermotorized disconnect 1802. Further, additional components shown in FIGS.2-17 may be included in the center motorized disconnect 1802. Furtherstill, components of the center motorized disconnect 1802 may beincluded in the wheel end disconnect embodiment shown in FIGS. 9-14.

As one embodiment, a motorized disconnect assembly comprises: a shifterassembly including an undulating gear track undulating between two endsof the shifter assembly in a direction of a rotation axis of aninterfacing shaft, the gear track trapped between fixed cam guides. In afurther embodiment of the above embodiment, the undulating gear track isin contact with a worm gear in contact with a worm. In any of the aboveembodiments, the worm is connected to an output shaft of an electricmotor. Additionally, in any of the above embodiments, the electric motoris adapted to rotate in a single direction while the interfacing shaftrotates in the single direction.

As another embodiment, a method for selectively engaging two shaftscomprises: during a first mode, holding a shifter assembly in a firstposition where the shifter assembly is engaged only with a first shaftvia a worm gear driven by a motor adapted to rotate the worm gear in afirst direction; upon receiving a command to shift to a second mode,driving the worm gear into contact with a gear track of the shifterassembly, the gear track oscillating between two ends of the shifterassembly, and moving the shifter assembly in a first axial direction andinto a second position where the shifter assembly is engaged with boththe first shaft and a second shaft; and upon receiving a command toshift back to the first mode, driving the worm gear in the firstdirection, and moving the shifter assembly in a second axial directionuntil the shifter assembly reaches the first position, the second axialdirection opposite the first axial direction. In a further embodiment ofthe above embodiment, the first mode is a two-wheel drive mode and thesecond mode is a four-wheel drive mode. As another further embodiment ofany of the above embodiments, the command to shift to the second modeand the command to shift back to the first mode is received by acontroller coupled to the shifter assembly, the controller operating themotor. As yet another embodiment of any of the above embodiments, thecontroller further includes programming for communicating with anexternal vehicle controller for receiving the commands to shift to thefirst and second modes. As another embodiment of any of the aboveembodiments, the controller further includes inputs for receivingsignals from a magnetic position sensor to determine if the shifterassembly has reached the first or second positions. Further, in anotherembodiment of any of the above embodiments, the shifter assemblyincludes an even number of magnets attached around a circumference ofthe shifter assembly, the magnets aligning with the magnetic positionsensor upon rotation of the shifter assembly.

As yet another embodiment, a motorized disconnect assembly, comprises:an electric motor; a worm drive including a worm and a worm gear, theworm connected to an output shaft of the electric motor and the wormgear; a shifter assembly including a gear track in contact with the wormgear, the gear track oscillating between two ends of the shifterassembly, and a clutch ring for selectively engaging a first shaft in afirst mode and engaging both the first shaft and a second shaft in asecond mode, the two modes corresponding to moving the shifter assemblylinearly into a first position and a second position, the first positionlocated at a different axial position than the second position; and acontroller with computer-readable instructions stored in non-transitorymemory for adjusting the shifter assembly into the first and secondpositions based on a request from a control system external to themotorized disconnect assembly. In a further embodiment of the aboveembodiment, the assembly further comprises one or more springs foraxially positioning the clutch ring when teeth of the clutch ringmisalign with teeth of the second shaft, wherein axial movement of theclutch ring occurs after axial movement of the shifter assembly uponalignment of the teeth of the clutch ring and second shaft. In anadditional embodiment of any of the above embodiments, the clutch ringrotates independent of the shifter assembly. As yet another embodimentof any of the above embodiments, the clutch ring moves axially with theshifter assembly. In a further embodiment of any of the aboveembodiments, the assembly further comprises a housing shaped to containthe shifter assembly. As still another embodiment of any of the aboveembodiments, the assembly further comprises a seal located on a side ofthe housing, the seal in contact with the first shaft.

As another embodiment, a system comprises: a controller (e.g., hubcontroller) disposed on a motorized disconnect assembly of a vehicle andthat is operable to: activate an electric motor to rotate a worm gearcoupled to the motor in a first direction in order to engage androtatably couple a first shaft with a second shaft, the worm gearcoupled to an oscillating gear track of a shifter assembly, theoscillating gear track coupled to a clutch ring adapted to engage withthe second shaft; and activate the electric motor to continue rotatingthe worm gear in the first direction in order to disengage the clutchring from the second shaft and decouple the first shaft and the secondshaft. In a further embodiment of the above embodiment, the controlleris in communicative connection with a vehicle controller locatedexternal to the motorized disconnect assembly. As yet another embodimentof any of the above embodiments, the electric motor turns an outputshaft equipped with a worm engaged with the worm gear. As a furtherembodiment of any of the above embodiments, the system further comprisesa control assembly containing the hub controller. In a furtherembodiment of any of the above embodiments, the control assembly furtherincludes a housing attached to a shifter structure of the motorizeddisconnect assembly.

As yet another embodiment, a method for operating a motorized disconnectassembly, comprises: receiving a request at a hub controller of acontrol assembly of the disconnect assembly from a vehicle controller toadjust a shifter assembly coupled to the control assembly into arequested position, the requested position being one of a connectedposition connecting two rotatable shafts or a disconnected position notconnecting the two rotatable shafts; determining a current position ofthe shifter assembly based on an output of a magnetic position sensorcoupled to the control assembly, the shifter assembly including aplurality of magnets disposed around a circumference of the shifterassembly; and activating an electric motor included in the controlassembly and coupled to the shifter assembly via a worm gear to rotatein a single direction and axially adjust the shifter assembly into therequested position when the current position is different than therequested position. In a further embodiment of the above embodiment, thevehicle controller is located external to the motorized disconnectassembly and includes instructions for sending shifting requests to oneor more disconnect assemblies separate from the motorized disconnectassembly. As another embodiment of any of the above embodiments, theconnected position corresponds to a four-wheel drive mode of a vehicle.In an additional embodiment of any of the above embodiments, thedisconnected position corresponds to a two-wheel drive mode of avehicle. In yet another embodiment of any of the above embodiments, theshifter assembly includes an undulating gear track in contact with theworm gear, the undulating gear track including repeating undulationsaround an outer circumference of the shifter assembly.

As another embodiment, a system comprises: a controller disposed on acenter motorized disconnect assembly of a vehicle, the center motorizeddisconnect assembly positioned along a mid-portion of a vehicle axle andproximate to a differential positioned between the axle and a driveshaft of the vehicle, the controller operable to: activate an electricmotor to rotate a worm gear coupled to the motor in a first direction inorder to engage and rotatably couple a first shaft with a second shaft,the worm gear coupled to an oscillating gear track of a shifterassembly, the oscillating gear track coupled to a clutch ring adapted toengage with the second shaft; and activate the electric motor tocontinue rotating the worm gear in the first direction in order todisengage the clutch ring from the second shaft and decouple the firstshaft and the second shaft. In a further embodiment of the aboveembodiments, the controller is in communicative connection with avehicle controller located external to the motorized disconnectassembly. In yet another embodiment of any of the above embodiments, theelectric motor turns an output shaft equipped with a worm engaged withthe worm gear. In still another embodiment of any of the aboveembodiments, the controller receives a vehicle signal indicating forwardor reverse vehicle motion and in response, drives the electric motor ina same direction as a direction of the vehicle motion. In an additionalembodiment of any of the above embodiments, the control assembly furtherincludes a shifter assembly housing attached to the shifter assembly ofthe motorized disconnect assembly.

As yet another embodiment, a center motorized disconnect assembly,comprises: an electric motor; a worm drive including a worm and a wormgear, the worm connected to an output shaft of the electric motor andthe worm gear; a shifter assembly including a gear track in contact withthe worm gear, the gear track oscillating between two ends of theshifter assembly, and a clutch ring for selectively engaging anintermediate shaft of an axle in a first mode and engaging both theintermediate shaft and a coupler shaft of the axle in a second mode, thecoupler shaft coupled to a wheel, the two modes corresponding to movingthe shifter assembly linearly into a first position and a secondposition, the first position located at a different axial position thanthe second position; a controller with computer-readable instructionsstored in non-transitory memory for adjusting the shifter assembly intothe first and second positions based on a request from a control systemexternal to the motorized disconnect assembly; and an outer casing fullyencasing the electric motor, worm drive, and shifter assembly, the outercasing arranged along a mid-portion of the axle proximate to adifferential arranged between the axle and a drive shaft. In a furtherembodiment of the above embodiment, the coupler shaft is coupled to ahalf shaft, the half shaft coupled to the wheel, and wherein theintermediate shaft is coupled to the differential, the differentialarranged between the intermediate shaft and a stub shaft of the axle andfurther coupled to the drive shaft of the vehicle. In another embodimentof any of the above embodiments, the intermediate shaft runs through anengine oil pan and wherein the motorized disconnect assembly anddifferential are arranged on opposite ends of the engine oil pan along alength of the axle. In yet another embodiment of any of the aboveembodiments, the stub shaft runs through the engine oil pan positionedon a first side of the differential and the motorized disconnectassembly is arranged on a second side of the differential, opposite thefirst side. In a further embodiment of any of the above embodiments, theaxle is a monobeam not including any half shafts and wherein the couplershaft is coupled directly to a u-joint of a wheel hub of the wheel.

The control methods and routines disclosed herein may be stored asexecutable instructions in non-transitory memory and may be carried outby the control system including the controller in combination with thevarious sensors, actuators, and other hardware described herein. Thespecific routines described herein may represent one or more of anynumber of processing strategies such as event-driven, interrupt-driven,multi-tasking, multi-threading, and the like. As such, various actions,operations, and/or functions illustrated may be performed in thesequence illustrated, in parallel, or in some cases omitted. Likewise,the order of processing is not necessarily required to achieve thefeatures and advantages of the example embodiments described herein, butis provided for ease of illustration and description. One or more of theillustrated actions, operations and/or functions may be repeatedlyperformed depending on the particular strategy being used. Further, thedescribed actions, operations and/or functions may graphically representcode to be programmed into non-transitory memory of the computerreadable storage medium in the disconnect and/or vehicle control system,where the described actions are carried out by executing theinstructions in a system including the various hardware components incombination with the electronic controller.

It will be appreciated that the configurations and routines disclosedherein are exemplary in nature, and that these specific embodiments arenot to be considered in a limiting sense, because numerous variationsare possible. The subject matter of the present disclosure includes allnovel and non-obvious combinations and sub-combinations of the varioussystems and configurations, and other features, functions, and/orproperties disclosed herein.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

The invention claimed is:
 1. A method for selectively engaging twoshafts, comprising: during a first mode, holding a clutch ring of ashifter assembly in a first position where the clutch ring is engagedonly with a first shaft via a worm gear driven by a motor adapted torotate the worm gear in only a first direction; upon receiving a commandto shift to a second mode, driving the worm gear into contact with agear track on a first gear of the shifter assembly, the gear trackincluding a plurality of teeth that are continuous around an outercircumference of the first gear, and moving the clutch ring in a firstaxial direction and into a second position where the clutch ring isengaged with both the first shaft and a second shaft; and upon receivinga command to shift back to the first mode, driving the worm gear in thefirst direction, and moving the clutch ring in a second axial directionuntil the shifter assembly reaches the first position, the second axialdirection opposite the first axial direction.
 2. The method of claim 1,wherein the first mode is a two-wheel drive mode and the second mode isa four-wheel drive mode.
 3. The method of claim 1, wherein the commandto shift to the second mode and the command to shift back to the firstmode are received by a controller coupled to the shifter assembly, thecontroller operating the motor.
 4. The method of claim 3, wherein thecontroller further includes programming for communicating with anexternal vehicle controller for receiving the commands to shift to thefirst and second modes.
 5. The method of claim 3, wherein the clutchring includes an inner surface including a first set of teeth, a secondset of teeth, and a non-toothed section separating the first set ofteeth and the second set of teeth, wherein the first shaft includes athird set of teeth adapted to mate with the first set of teeth, andwherein the second shaft includes a fourth set of teeth adapted to matewith the second set of teeth.